authorgravatar for git@vexu.euVeikka Tuominen <git@vexu.eu> 2020-12-26 02:36:12+02:00
committergravatar for git@vexu.euVeikka Tuominen <git@vexu.eu> 2020-12-26 02:36:12+02:00
loga50759325c95ad7dfd1fbf029759cf0a2608b3ab
tree8bdf7813a7b82e743ffc3dbc589314c94ba9473d
parent40aad4f47e1ab02a1ff6109f4b6f06af00d1f503
signaturelock-open Commit is signed but in an unrecognized format.

stage2: add error for unused labels

3 files changed, 40 insertions(+), 6 deletions(-)

src/Module.zig+1-1
......@@ -804,7 +804,7 @@ pub const Scope = struct {
804804 pub const Label = struct {
805805 token: ast.TokenIndex,
806806 block_inst: *zir.Inst.Block,
807 result_loc: astgen.ResultLoc,
807 used: bool = false,
808808 };
809809 };
810810
src/astgen.zig+19-4
......@@ -348,8 +348,9 @@ fn breakExpr(mod: *Module, parent_scope: *Scope, node: *ast.Node.ControlFlowExpr
348348
349349 const block_inst = blk: {
350350 if (node.getLabel()) |break_label| {
351 if (gen_zir.label) |label| {
351 if (gen_zir.label) |*label| {
352352 if (try tokenIdentEql(mod, parent_scope, label.token, break_label)) {
353 label.used = true;
353354 break :blk label.block_inst;
354355 }
355356 }
......@@ -407,8 +408,9 @@ fn continueExpr(mod: *Module, parent_scope: *Scope, node: *ast.Node.ControlFlowE
407408 continue;
408409 };
409410 if (node.getLabel()) |break_label| blk: {
410 if (gen_zir.label) |label| {
411 if (gen_zir.label) |*label| {
411412 if (try tokenIdentEql(mod, parent_scope, label.token, break_label)) {
413 label.used = true;
412414 break :blk;
413415 }
414416 }
......@@ -485,6 +487,9 @@ fn labeledBlockExpr(
485487 defer block_scope.instructions.deinit(mod.gpa);
486488
487489 try blockExprStmts(mod, &block_scope.base, &block_node.base, block_node.statements());
490 if (!block_scope.label.?.used) {
491 return mod.fail(parent_scope, tree.token_locs[block_node.label].start, "unused block label", .{});
492 }
488493
489494 block_inst.positionals.body.instructions = try block_scope.arena.dupe(*zir.Inst, block_scope.instructions.items);
490495 try gen_zir.instructions.append(mod.gpa, &block_inst.base);
......@@ -1398,7 +1403,7 @@ fn whileExpr(mod: *Module, scope: *Scope, rl: ResultLoc, while_node: *ast.Node.W
13981403 loop_scope.break_block = while_block;
13991404 loop_scope.continue_block = cond_block;
14001405 if (while_node.label) |some| {
1401 loop_scope.label = @as(?Scope.GenZIR.Label, Scope.GenZIR.Label{
1406 loop_scope.label = @as(?Scope.GenZIR.Label, Scope.GenZIR.Label{
14021407 .token = some,
14031408 .block_inst = while_block,
14041409 });
......@@ -1465,6 +1470,11 @@ fn whileExpr(mod: *Module, scope: *Scope, rl: ResultLoc, while_node: *ast.Node.W
14651470 condbr.positionals.else_body = .{
14661471 .instructions = try else_scope.arena.dupe(*zir.Inst, else_scope.instructions.items),
14671472 };
1473 if (loop_scope.label) |some| {
1474 if (!some.used) {
1475 return mod.fail(scope, tree.token_locs[some.token].start, "unused while label", .{});
1476 }
1477 }
14681478 return &while_block.base;
14691479}
14701480
......@@ -1555,7 +1565,7 @@ fn forExpr(mod: *Module, scope: *Scope, rl: ResultLoc, for_node: *ast.Node.For)
15551565 loop_scope.break_block = for_block;
15561566 loop_scope.continue_block = cond_block;
15571567 if (for_node.label) |some| {
1558 loop_scope.label = @as(?Scope.GenZIR.Label, Scope.GenZIR.Label{
1568 loop_scope.label = @as(?Scope.GenZIR.Label, Scope.GenZIR.Label{
15591569 .token = some,
15601570 .block_inst = for_block,
15611571 });
......@@ -1646,6 +1656,11 @@ fn forExpr(mod: *Module, scope: *Scope, rl: ResultLoc, for_node: *ast.Node.For)
16461656 condbr.positionals.else_body = .{
16471657 .instructions = try else_scope.arena.dupe(*zir.Inst, else_scope.instructions.items),
16481658 };
1659 if (loop_scope.label) |some| {
1660 if (!some.used) {
1661 return mod.fail(scope, tree.token_locs[some.token].start, "unused for label", .{});
1662 }
1663 }
16491664 return &for_block.base;
16501665}
16511666
test/stage2/test.zig+20-1
......@@ -1207,7 +1207,7 @@ pub fn addCases(ctx: *TestContext) !void {
12071207
12081208 {
12091209 var case = ctx.exe("break/continue", linux_x64);
1210
1210
12111211 // Break out of loop
12121212 case.addCompareOutput(
12131213 \\export fn _start() noreturn {
......@@ -1296,4 +1296,23 @@ pub fn addCases(ctx: *TestContext) !void {
12961296 "",
12971297 );
12981298 }
1299
1300 {
1301 var case = ctx.exe("unused labels", linux_x64);
1302 case.addError(
1303 \\comptime {
1304 \\ foo: {}
1305 \\}
1306 , &[_][]const u8{":2:5: error: unused block label"});
1307 case.addError(
1308 \\comptime {
1309 \\ foo: while (true) {}
1310 \\}
1311 , &[_][]const u8{":2:5: error: unused while label"});
1312 case.addError(
1313 \\comptime {
1314 \\ foo: for ("foo") |_| {}
1315 \\}
1316 , &[_][]const u8{":2:5: error: unused for label"});
1317 }
12991318}